Fecal carriage of Escherichia coli O157:H7 and carcass contamination in cattle at slaughter in northern Italy

Authors

  • Silvia Alonso E. coli Reference Laboratory (LREC), Faculty of Veterinary, University of Santiago de Compostela, Lugo, Spain Department of Public Health and Animal Pathology, University of Bologna, Bologna, Italy
  • Azucena Mora E. coli Reference Laboratory (LREC), Faculty of Veterinary, University of Santiago de Compostela, Lugo, Spain
  • Miguel Blanco E. coli Reference Laboratory (LREC), Faculty of Veterinary, University of Santiago de Compostela, Lugo, Spain
  • Jesús E. Blanco E. coli Reference Laboratory (LREC), Faculty of Veterinary, University of Santiago de Compostela, Lugo, Spain
  • Ghizlane Dahbi E. coli Reference Laboratory (LREC), Faculty of Veterinary, University of Santiago de Compostela, Lugo, Spain
  • María T. Ferreiro E. coli Reference Laboratory (LREC), Faculty of Veterinary, University of Santiago de Compostela, Lugo, Spain
  • Cecilia López E. coli Reference Laboratory (LREC), Faculty of Veterinary, University of Santiago de Compostela, Lugo, Spain
  • Leonardo Alberghini Department of Public Health and Animal Pathology, University of Bologna, Bologna, Italy
  • Sabrina Albonetti Department of Public Health and Animal Pathology, University of Bologna, Bologna, Italy
  • Aurora Echeita Laboratory of Bacteriology, National Microbiology Centre, Carlos III Health Institute, Madrid, Spain
  • Marcello Trevisani Department of Public Health and Animal Pathology, University of Bologna, Bologna, Italy
  • Jorge Blanco E. coli Reference Laboratory (LREC), Faculty of Veterinary, University of Santiago de Compostela, Lugo, Spain

Keywords:

Escherichia coli O157, H7, Shiga-toxins, verotoxins, phage typing, abattoir, carcass contamination

Abstract

Feedlot cattle slaughtered at a large abattoir in northern Italy during 2002 were examined for intestinal carriage and carcass contamination with Escherichia coli O157:H7. Carcass samples were taken following the excision method described in the Decision 471/2001/EC, and fecal material was taken from the colon of the calves after evisceration. Bacteria were isolated and identified according to the MFLP-80 and MFLP-90 procedures (Food Directorate’s Health Canada’s). Eighty-eight non-sorbitol-fermenting E. coli O157:H7 isolates were obtained from 12 of the 45 calves examined. In particular, E. coli O157:H7 isolates were found in 11 (24%) fecal and five (11%) carcass samples. PCR analysis showed that all 11 fecal samples and five carcass samples carried eae-γ1-positive E. coli O157:H7 isolates. In addition, genes encoding Shigatoxins were detected in O157:H7 isolates from nine and two of those 11 fecal and five carcasses, respectively. A representative group of 32 E. coli O157:H7 isolates was analyzed by phage typing and DNA macrorestriction fragment analysis (PFGE). Five phage types (PT8, PT32v, PT32, PT54, and PT not typable) and seven (I–VII) distinct restriction patterns of similarity > 85% were detected. Up to three different O157:H7 strains in an individual fecal sample and up to four from the same animal could be isolated. These findings provide evidence of the epidemiological importance of subtyping more than one isolate from the same sample. Phage typing together with PFGE proved to be very useful tools to detect cross-contamination among carcasses and should therefore be included in HACCP programs at abattoirs. The results showed that the same PFGE-phage type E. coli O157:H7 profile was detected in the fecal and carcass samples from an animal, and also in two more carcasses corresponding to two animals slaughtered the same day. [Int Microbiol 2007; 10(2):109-116]

Author Biographies

Silvia Alonso, E. coli Reference Laboratory (LREC), Faculty of Veterinary, University of Santiago de Compostela, Lugo, Spain Department of Public Health and Animal Pathology, University of Bologna, Bologna, Italy

E. coli Reference Laboratory (LREC), Faculty of Veterinary, University of Santiago de Compostela, Lugo, Spain Department of Public Health and Animal Pathology, University of Bologna, Bologna, Italy

Azucena Mora, E. coli Reference Laboratory (LREC), Faculty of Veterinary, University of Santiago de Compostela, Lugo, Spain

E. coli Reference Laboratory (LREC), Faculty of Veterinary, University of Santiago de Compostela, Lugo, Spain

Miguel Blanco, E. coli Reference Laboratory (LREC), Faculty of Veterinary, University of Santiago de Compostela, Lugo, Spain

E. coli Reference Laboratory (LREC), Faculty of Veterinary, University of Santiago de Compostela, Lugo, Spain

Jesús E. Blanco, E. coli Reference Laboratory (LREC), Faculty of Veterinary, University of Santiago de Compostela, Lugo, Spain

E. coli Reference Laboratory (LREC), Faculty of Veterinary, University of Santiago de Compostela, Lugo, Spain

Ghizlane Dahbi, E. coli Reference Laboratory (LREC), Faculty of Veterinary, University of Santiago de Compostela, Lugo, Spain

E. coli Reference Laboratory (LREC), Faculty of Veterinary, University of Santiago de Compostela, Lugo, Spain

María T. Ferreiro, E. coli Reference Laboratory (LREC), Faculty of Veterinary, University of Santiago de Compostela, Lugo, Spain

E. coli Reference Laboratory (LREC), Faculty of Veterinary, University of Santiago de Compostela, Lugo, Spain

Cecilia López, E. coli Reference Laboratory (LREC), Faculty of Veterinary, University of Santiago de Compostela, Lugo, Spain

E. coli Reference Laboratory (LREC), Faculty of Veterinary, University of Santiago de Compostela, Lugo, Spain

Leonardo Alberghini, Department of Public Health and Animal Pathology, University of Bologna, Bologna, Italy

Department of Public Health and Animal Pathology, University of Bologna, Bologna, Italy

Sabrina Albonetti, Department of Public Health and Animal Pathology, University of Bologna, Bologna, Italy

Department of Public Health and Animal Pathology, University of Bologna, Bologna, Italy

Aurora Echeita, Laboratory of Bacteriology, National Microbiology Centre, Carlos III Health Institute, Madrid, Spain

Laboratory of Bacteriology, National Microbiology Centre, Carlos III Health Institute, Madrid, Spain

Marcello Trevisani, Department of Public Health and Animal Pathology, University of Bologna, Bologna, Italy

Department of Public Health and Animal Pathology, University of Bologna, Bologna, Italy

Jorge Blanco, E. coli Reference Laboratory (LREC), Faculty of Veterinary, University of Santiago de Compostela, Lugo, Spain

E. coli Reference Laboratory (LREC), Faculty of Veterinary, University of Santiago de Compostela, Lugo, Spain

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Published

2010-01-26

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Research Articles